first pass at release job

[seanstory]

Closes https://github.com/elastic/enterprise-search-team/issues/4578

Introduces a release job that can be triggered from buildkite

Checklists

Pre-Review Checklist

• [x] this PR has a meaningful title
• [x] this PR links to all relevant github issues that it fixes or partially addresses
• [x] if there is no GH issue, please create it. Each PR should have a link to an issue
• [x] this PR has a thorough description
• [ ] Covered the changes with automated tests
• [x] Tested the changes locally
• [x] Added a label for each target release version (example: v7.13.2, v7.14.0, v8.0.0)
• [ ] Considered corresponding documentation changes